1. Field of the Invention
The invention relates to a scanning electron microscope, and in particular to a scanning electron microscope with a diamond film.
2. Description of the Related Art
Along with rapid integration of semiconductor devices, a scanning electron microscope (SEM) is used for observation and inspection of a refined circuit pattern. A scanning electron microscope scans a specimen with electron beams, detects secondary electrons emitted from the specimen following a bombardment by electron beams, and displays a secondary electron image representing the scanned objects on a display screen. This technology is suitable for observation of minute structures for the semiconductor manufacturing fields.
A conventional scanning electron microscope is disclosed in FIG. 1. The scanning electron microscope 1 comprises an electron beam source 2, a condenser lens 4, a base plate 5, an aperture 6, a scanning unit 7, an objective 8, a specimen 9, and a detector 11.
The electron beam source 2 generates a primary electron beam 3. The condenser lens 4 converges the primary electron beam 3. The aperture 6 is formed in the base plate 5 for passing of the primary electron beam 3. The scanning unit 7 two-dimensionally scans the specimen 9 with the primary electron beam 3. The objective 8 disposed between the scanning unit 7 and the specimen 9 focuses the primary electron beam 3. The detector 11 detects secondary electrons generated by the specimen 9 irradiated with the primary electron beam 3.
The conventional base plate having the aperture is formed of molybdenum (Mo). However, the edge of the aperture is easily transformed by continuous electron beam shooting due to insufficient hardness of the molybdenum (Mo) material, resulting in deterioration of image quality. Generally, the base plate should be replaced every month, thus resulting in additional costs.